The effects of arithmetic task difficulty and performance level on EEG alpha asymmetry

Hemispheric Lateralization of Cognitive Evoked Blood Flow Velocity Changes Assessed by Simultaneous Bilateral Transcranial Doppler Sonography

“…As CBFV rises reflect task complexity [24], the trend towards a left lateralization in the ACA but not in the MCA could be caused by the diffi culty of our task. Increasing task difficulty was shown to provoke left frontal involvement [31], In contrast to the assumption of Kelley et al [22] we did not find any signif icant effect of the sequence of insonation of the different arteries. Thus, habituation effects seem to be far less strong than expected and a gross localization of cortical areas involved in certain cognitive processes is possible by sbTCD.…”

The Time Course of Parietal Activation in Single-digit Multiplication: Evidence from Event-related Potentials

“…decreased alpha power) as an index of activation. Earle (1985) found a relatively stronger left compared to right parietal activation for simple to moderate tasks, whereas alpha power asymmetry decreased for the most difficult task. Hence, difficult arithmetic tasks seem to involve both left and right parietal areas.…”

“…Further evidence for a stronger involvement of right parietal areas with increased arithmetic-task difficulty stems from an EEG study by Earle (1985) using EEG-desynchronization (i.e. decreased alpha power) as an index of activation.…”

Cognitive and gender factors influencing navigation in a virtual environment

“…Cognitive activity results in desynchronisation of EEG in cortical regions where the activity occurs (Papanicolaou, Loring, Deutsch & Eisenberg, 1986) and this can be quanti"ed by power analysis. Thus, the greater right hemisphere high-frequency asymmetry in the verbal-sequential group can be taken as evidence of greater right hemisphere involvement (or cognitive e!ort) during VE navigation (Donchin et al, 1977;Earle, 1985). This result is unlikely to be due to the motor demands of the task, which only required occasional button presses with the right hand (see Donchin et al, 1977;Davidson et al, FACTORS AFFECTING VIRTUAL NAVIGATION 1990).…”

“…One method for examining this is to record the electroencephalogram (EEG) and compute the asymmetry of synchronized brain wave power (Pivik, Broughton, Coppola, Davidson, Fox & Nuwer, 1993). Greater asymmetry should be evident in individuals who exert greater cognitive e!ort to perform a task such as navigation (Earle, 1985). The block design sub-test of the Wechsler Adult Intelligence (revised) test may also be a useful indicator of the visual-spatial skills required for navigation.…”